Fracture Initiation Due to Asymmetric Impact Loading of an Edge Cracked Plate
Abstract
The two dimensional elastodynamic problem of a semi-infinite plate containing an edge crack is considered. Initially, the plate is stress free and at rest. To simulate the asymmetric impact of a projectile on the cracked edge of the plate, a normal velocity is suddenly imposed on the boundary of the plate on one side of the edge crack. The boundary of the plate and the crack faces are otherwise traction free. Due to the nature of the loading, a combined mode I and mode II transient stress intensity factor is induced at the crack tip. This stress intensity factor history is determined exactly by linear superposition of several more readily obtainable stress wave propagation solutions, including a fundamental solution arising from a particular stress wave propagation solutions, including a fundamental solution arising from a particular problem in the dynamic theory of the elastic dislocations. The stress intensity factor histories are determined for the time interval from initial loading until the first scattered wave at the crack tip is reflected at the edge and arrives at the crack tip again. For an applied velocity with step function time dependence, the mode I stress intensity factor monotonically decreases and that of mode II increases until the arrival of the Rayleigh wave, it then slightly decreases for short duration, and then increases again. In experiments of fracture initiation in a high strength steel the fracture either grew off at an angle as a tensile crack or strain ahead as a shear fracture.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1988
- Accession Number
- ADA204533
Entities
People
- Lambert Ben Freund
- Y. J. Lee
Organizations
- Brown University